Camera system and camera control method

ABSTRACT

A camera system includes: a first camera and a second camera; a camera adaptor box; and a camera control unit.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a camera system and a camera controlmethod that are suitable for use in applications in which 3D (threedimensional) images are generated from the images taken by two units ofcameras, for example.

2. Description of the Related Art

3D camera systems have been in use in which 3D images are obtained bycombining the images separately taken by two different cameras.

Referring to FIG. 15, there is shown an exemplary configuration of arelated-art 3D camera system 101.

The 3D camera system 101 has two cameras 110 a and 110 b, control panels111 a and 111 b for controlling the operation of each of the cameras 110a and 110 b, and a monitor 112 on which images outputted from thecameras 110 a and 110 b are displayed.

A reference signal is directly entered in each of cameras 110 a and 110b and each of the cameras 110 a and 110 b directly outputs a taken imageto an external apparatus.

Referring to FIG. 16, there is shown an exemplary configuration of arelated-art 3D camera system 102.

The 3D camera system 102 has camera control units 113 a and 113 b thatare connected to cameras 110 a and 110 b, respectively, therebyoutputting control signals to the camera 110 a and 110 b and outputtingimages received from the cameras 110 a and 110 b. The cameras 110 a and110 b are connected to the camera control units 113 a and 113 b withsingle link digital optical transmission paths capable of transmittingvideo signals at a transfer rate of 1.5 Gbps, for example. The cameracontrol units 113 a and 113 b are also connected to a simultaneouscontrol apparatus 114 configured to simultaneously control theoperations of the camera 110 a and camera 110 b. From this simultaneouscontrol apparatus 114, the restricted functions of the cameras 110 a and110 b can be simultaneously controlled. This function is originallyintended to simultaneously control two or more system cameras; in thisexample, this function is applied to the control of the two cameras 110a and 110 b.

Referring to FIG. 17, there is shown an exemplary configuration of arelated-art 3D camera system 103.

The 3D camera system 103 has a configuration in which two or more of the3D camera systems 102 shown in FIG. 16 are operated in parallel.Simultaneous control apparatuses 114 a through 114 c are arranged forthe different 3D camera systems 102, thereby controlling the cameras 110a and cameras 110 b of each of these 3D camera systems 102.

However, the above-mentioned related-art technologies have no apparatusthat is configured to simultaneously totally control the 3D cameras inone 3D camera system.

Japanese Patent Laid-open No. 2002-77947 discloses a technology in which3D images are obtained by adjusting an inter-image positional shift oran inter-image rotational shift caused between two or more images havinga parallax.

SUMMARY OF THE INVENTION

It should be noted that generating a 3D image requires two images havingdifferent parallaxes. At this moment, an engineer must operate not onlythe camera control units and the simultaneous control apparatus, butalso adjust two cameras 110 a and 110 b. Therefore, the engineer mustcarry out the job that is approximately double when there is only onecamera.

For example, in relaying a sports program in a 3D manner, two or more 3Dcameras must be arranged at various locations. In addition, because thecamera adjustment is required during a relay operation, two or morecameras must be adjusted at the same time. However, the movements ofsubjects are generally quick in a sports program for example. This notonly requires engineers of the high technical operation skills inexecuting image adjustment, but also makes the 3D camera systemcomplicated, thereby increasing the operation load.

In consideration of the above-mentioned problems, the adjustment of thetwo cameras 110 a and 110 b has been practiced by use of camera linkingcapabilities such as master-slave realized by the simultaneous controlapparatuses 114, 114 a through 114 c, for example. However, as shown inthe 3D camera system 103, operating two or more 3D camera systems 102requires the installation of the same number of master-slave functionsas the number of 3D cameras, the cameras 110 a and 110 b, on the 3Dcamera system 103. This also causes a problem of increasing the systemconfiguration.

Further, use of a rig mechanism (or a half-mirror mechanism), one ofmechanisms for arranging the cameras 110 a and 110 b in order toconfigure the 3D camera system 101, requires the inversion of takenimages. Therefore, use of a 3D camera system based on the rig mechanismrequires to match the timing of taking a subject by the cameras 110 aand 110 b with the phase of video signals outputted by the cameras 110 aand 110 b; otherwise, the taken images are delayed to cause anincomplete resultant 3D image.

Therefore, the present invention addresses the above-identified andother problems associated with related-art methods and apparatuses andsolves the addressed problems by providing a camera system and a cameracontrol method that are configured to facilitate the operation of two ormore cameras without using complicated procedures by simplifying thecamera system configuration in generating 3D images.

According to an embodiment of the present invention, there is provided acamera system including: a first camera and a second camera; a cameraadaptor box; and a camera control unit. The camera adaptor box has: acorrection control block configured to set a difference of the secondcamera to the first camera on the basis of information indicative of animaging state in the case where the first camera and the second cameraexecute imaging operations by a first control value and a second controlvalue outputted from the first camera and the second camera,respectively, output the first control value to the first camera, andoutput the second control value with the difference corrected to thesecond camera; an imaging timing adjustment block configured to adjustimaging timings of the first camera and the second camera; and a firstvideo output block configured to output video received from the firstcamera and the second camera that have executed imaging operations basedon the first control value and the second control value with the imagetiming adjusted. The camera control unit has: an instruction valueoutput block configured to output, to the correction control block,instruction values for instructing operations of the first camera andthe second camera that provide the first control value and the secondcontrol value; and a second video output block configured to outputvideo received from the first video output block.

As described above, It is possible to set the difference of the secondcamera relative to the first camera, output the first control value tothe first camera, and output a second control value with a differencecorrected to a second camera in order to operate two units of cameras.

According to another embodiment of the present invention, there isprovided a camera control method including the steps of: setting, by acamera adaptor box configured to control operations of a first cameraand a second camera, a difference of the second camera to the firstcamera on the basis of information indicative of an imaging state in thecase where the first camera and the second camera execute imagingoperations by a first control value and a second control value outputtedfrom the first camera and the second camera, respectively, outputtingthe first control value to the first camera, and outputting the secondcontrol value with the difference corrected to the second camera; andadjusting imaging timings of the first camera and the second camera. Themethod further includes the steps of: outputting, by a first videooutput block, video received from the first camera and the second camerathat have executed imaging operations based on the first control valueand the second control value with the imaging timing adjusted;outputting, by a camera control unit configured to control operations ofthe first camera and the second camera via the camera adaptor box, aninstruction value for instructing operations of the first camera and thesecond camera that provide the first control value and the secondcontrol value; and outputting the video received from the first videooutput block.

According to the present invention, a first control value is outputtedto a first camera and, at the same time, a second control value with adifference corrected is outputted to a second camera in order to operatetwo units of cameras. Therefore, an engineer can control the two unitsof cameras as if the two units of cameras were one unit of camera. Thisnovel configuration facilitates the configuration of the camera system,thereby saving the engineer the load of taking images for 3D imaging. Indoing so, the two units of cameras output images that is homogenous toeach other because the differences between these images are corrected.

At this time, the two units of cameras output images that are homogenousto each other because the differences between these images arecorrected. This novel configuration provides advantages of providing theoutput suitable for 3D images that are displayed by combining twoimages.

In order to operate a system of two or more (3D) cameras or largelyextend the distance between the camera, the control panel, and thedevice that receives video signals, a system configuration having acamera control unit (CCU) can be provided to reduce the volume of wiringto the camera side, thereby realizing the flexible operation of thelinked imaging with two or more cameras such as live system cameras.

This novel configuration enables 3D cameras to realize a system cameraconfiguration substantially similar to that based on related-art 2Dimaging.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an exemplary configuration ofa 3D camera system made up of camera heads and a camera adaptor boxpracticed as one embodiment of the invention;

FIG. 2 is a schematic diagram illustrating an exemplary configuration ofa 3D camera system in which a camera control unit is added to the 3Dcamera system shown in FIG. 1;

FIG. 3 is a schematic diagram illustrating an exemplary configuration ofa 3D camera system in which the two or more 3D camera systems shown inFIG. 2 are arranged in parallel;

FIGS. 4A and 4B are schematic diagrams illustrating an exemplary cameramount on which the two 3D cameras shown in FIG. 1 are mounted;

FIG. 5 is a block diagram illustrating an exemplary internalconfiguration of the 3D camera system shown in FIG. 1;

FIG. 6 is a block diagram illustrating an exemplary internalconfiguration of a camera adaptor box shown in FIG. 1;

FIG. 7 is a block diagram illustrating an exemplary internalconfiguration of a video interface block shown in FIG. 5;

FIG. 8 is a block diagram illustrating exemplary internal configurationsof the camera adaptor box and camera heads shown in FIG. 1;

FIGS. 9A and 9B are pictures indicative of exemplary images taken byscan lines in the embodiment shown in FIG. 1;

FIG. 10 is a graph indicative of an exemplary relation between irisadjustment value and iris aperture in the cameras shown in FIG. 1;

FIG. 11 is a graph indicative of an example of correcting the irisaperture of the cameras shown in FIG. 1 by use of a correction function;

FIG. 12 is a graph indicative of an example of correcting the irisaperture of the cameras shown in FIG. 1 by use of a correction functionapproximating a line plot;

FIGS. 13A, 13B, and 13C are pictures indicative of display examples ofimages shown on a viewfinder block shown in FIG. 1;

FIGS. 14A, 14B, and 14C are pictures indicative of display examplesshown on the viewfinder block shown in FIG. 1;

FIG. 15 is a schematic diagram illustrating a related-art 3D camerasystem;

FIG. 16 is a schematic diagram illustrating another related-art 3Dcamera system; and

FIG. 17 is a schematic diagram illustrating still another related-art 3Dcamera system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention will be described in further detail by way of embodimentsthereof with reference to the accompanying drawings. The descriptionwill be made in the following order.

1. One embodiment of the invention (a camera control function; namely,an example in which two or more camera heads are used for a 3D camerasystem)2. Variations to the above-mentioned embodiment

1. One Embodiment of the Invention Exemplary Configuration of a 3DCamera System

The following describes one embodiment of the present invention withreference to FIGS. 1 through 14. With one embodiment of the invention,examples of 3D camera systems each having a camera adaptor box 12configured to output images taken by two camera heads 10 a and 10 b toan external apparatus by giving image taking instructions to thesecamera heads 10 a and 10.

Now, referring to FIG. 1, there is shown an exemplary configuration of a3D camera system 1.

The 3D camera system 1 has an optical system, an image device, and soon, not shown, and has a camera head 10 a and a camera head 10 b thatare configured to output images of a taken subject. It should be notedthat the camera head 10 a and the camera head 10 b are fixed on a wallfor example and have no function of recording taken images.

In the following description, it is assumed that an image outputted bythe camera head 10 a be used for the right channel (or the right eye)and an image outputted by the camera head 10 b be used for the leftchannel (or the left eye).

Further, the 3D camera system 1 has a camera adaptor box (CAB) 12configured to control the operations of the camera head 10 a and thecamera head 10 b to execute predetermined processing on the imagesreceived from the camera head 10 a and the camera head 10 b, therebyoutputting the processed images. The camera adaptor box 12 has aviewfinder block 13 configured to display the images of a subject takenby the camera head 10 a and the camera head 10 b, under the control of avideo interface block 24 (refer to FIG. 5 below).

Referring to FIG. 2, there is shown an exemplary configuration of a 3Dcamera system 2.

The 3D camera system 2 has a camera head 10 a and a camera head 10 b, acamera adaptor box 12, and a camera control unit (CCU) 14 that isconnected to the camera adaptor box 12 via a camera cable 15. For thecamera cable 15, a wide-band digital optical transmission path capableof transmitting massive amounts of optical digital signals. In thisexample, as compared with a related-art 1.5 Gbps data rate, embodimentsof the present invention assume an optical data transmission rate of 3.7Gbps. It should be noted here that embodiments of the present inventionallow video data compression to realize narrow-band transmission (aswith related-art technologies).

The camera adaptor box 12 collects images outputted from the cameraheads 10 a and 10 b and transmits these images to the camera controlunit 14 over the camera cable 15. As required, the camera adaptor box 12executes processing, such as inverting images entered from the cameraheads 10 a and 10 b and delaying an output signal so as to providesignal in-phasing.

Between the camera control unit 14 and the camera adaptor box 12, awideband (more than double a related-art band) communication interfaceis used. This interface can simultaneously transmit the images outputtedfrom the camera heads 10 a and 10 b. In addition, the camera controlunit 14 has a communication interface compliant with 3G-HDI for examplethrough which the camera control unit 14 can transfer video signals toan external device at high speeds. The camera control unit 14 outputs acontrol signal received from the a control panel 11 to the cameraadaptor box 12 and outputs a video signal received from the cameraadaptor box 12 to a display apparatus and a recording apparatus, notshown. Further, the camera control unit 14 is controlled by the controlpanel 11 operated by an engineer.

As described above, because the camera adaptor box 12 is arrangedbetween the camera heads 10 a and 10 b and the camera control unit 14,it appears that, from the camera adaptor box 12, the operation of onecamera is being controlled from the camera adaptor box 12.

Referring to FIG. 3, there is shown an exemplary configuration of a 3Dcamera system 3.

The 3D camera system 3 is configured in which the 3D camera systems 2shown in FIG. 2 are operated in parallel. The camera control unit 14 isarranged for each of the 3D camera systems 2. The operation timingbetween the camera heads 10 a and 10 b arranged for each 3D camerasystem 2 is controlled.

The camera control unit 14 is also connected to a simultaneous controlapparatus 6 that simultaneously controls the operations of the cameraheads 10 a and 10 b arranged for the 3D camera system 2 that areoperated in parallel. The camera adaptor box 12 can differentiate acontrol value by a difference in the operation of the camera head 10 bfor the camera head 10 a, thereby controlling the operations of thecamera heads 10 a and 10 b as if these cameras are one unit of camera.Consequently, as compared with related-art 3D camera systems 101 through103, the 3D camera system 3 can be simplified in configuration. Thecamera head 10 a, the camera head 10 b, the camera adaptor box 12, thecamera control unit 14, and the simultaneous control apparatus 6 areinterconnected by a network. The connection between these components isrealized by coaxial cables, triaxial cables, optical fiber cables,wireless communication, and other communication media.

Referring to FIGS. 4A and 4B, there is shown an exemplary configurationof a mount (RIG) 7 on which the camera heads 10 a and 10 b are mounted.

FIG. 4A shows an exemplary configuration of the camera heads 10 a and 10b when the mount 7 is viewed from one side.

Basically, it is known that, if the camera heads 10 a and 10 b bearranged with the zoom of the camera heads 10 a and 10 b equal one and alens distance thereof matched with the human eye, a 3D image obtainedfrom the images taken the camera heads 10 a and 10 b thus arranged looksnatural. However, because the housings of the camera heads 10 a and 10 bare relatively large and, if the camera heads 10 a and 10 b are arrangedside by side for imaging, a subject is taken with a parallax wider thanthat of the human eyes, resulting in an unnatural 3D image. Hence, themount 7 has a half mirror 8. The first camera head 10 a is arranged at aposition where the image of a subject is directly enters through thehalf mirror 8. The second camera head 10 b is arranged at a positionwhere the image of the subject enters after being reflected from thehalf mirror 8. Thus, the camera heads 10 a and 10 b are arranged suchthat the optical axes of the lenses of the camera heads 10 a and 10 bvertically cross each other.

FIG. 4B shows an example of how the half mirror 8 looks when viewed fromthe direction of arrow 9. The camera heads 10 a and 10 b are arranged onthe mount 7 by shifting from each other in a distance obtained by theparallax of the human eyes. Hence, the lens of the camera head 10 alooking through the half mirror 8 and the lens of the camera head 10 blooking as reflected from the half mirror 8 are shifted from each otherin the horizontal direction. Thus, arranging the half mirror 8 on themount 7 allows the installation of the camera heads 10 a and 10 b inmatch with the parallax of the human eyes, thereby producing a naturallylooking 3D image.

Referring to FIG. 5, there is shown an exemplary internal configurationof the 3D camera system 2.

The camera head 10 a has an imaging device 16 that outputs a videosignal. The imaging device 16 is made up of a CCD (Charge CoupledDevice) imager or a CMOS (Complementary Metal Oxide Semiconductor)sensor, for example.

The camera head 10 a has a PLL (Phase Locked Loop) circuit 17 forexecuting a PLL operation under the control of the camera adaptor box 12and a timing generation circuit 18 for generating an imaging timingsignal of the imaging device 16 by a PLL operation of the PLL circuit17. In addition, the camera head 10 a has a CPU 19 a for controllingeach of the components of the camera system and a video processor 20that executes predetermined processing on a video signal outputted fromthe imaging device 16 to output the processed video signal to the cameraadaptor box 12.

It should be noted that the camera head 10 b is generally the same inconfiguration as the camera head 10 a except a CPU 19 b instead of theCPU 19 a. Therefore, the similar components of the camera head 10 b aredenoted by the same reference numbers as those of the camera head 10 aand the description of the similar components will be skipped for thebrevity of description.

The camera adaptor box 12 has a PLL circuit 21 for executing a PLLoperation under the control of the camera control unit 14 and a timinggeneration circuit 22 for generating an imaging timing signal forcontrolling the imaging timings of the camera heads 10 a and 10 b by aPLL operation of the PLL circuit 21. In addition, the camera adaptor box12 has a CPU 23 for controlling each component of the camera adaptor box12, a video interface block 24 for executing predetermined processing onthe video signals supplied from the camera heads 10 a and 10 b to outputthe processed signals to the camera control unit 14, and a viewfinderblock 13. A viewfinder signal is supplied to the viewfinder block 13from the video interface block 24. The images of a subject are shown onthe camera heads 10 a and 10 b, allowing the engineer to check the takenimages (refer to FIGS. 13A to 14C to be described later).

The camera control unit 14 has a PLL, circuit 31 that executes a PLLoperation on the basis of a reference signal supplied from an externalapparatus, not shown, and a timing generation circuit 32 that generatesa timing signal for controlling the operation timing of the cameraadaptor box 12 by a PLL operation of the PLL circuit 31. In addition,the camera control unit 14 has a CPU 33 that controls the processing ofeach component of the camera control unit 14 in cooperation with the CPU23 of the camera adaptor box 12 and a video interface block 34 thatexecutes predetermined processing on the video signal supplied from thecamera adaptor box 12 to output the processed video signal to anexternal apparatus, not shown.

The following describes the operation of each component mentioned above.

The CPU 33 of the camera control unit 14 functions as an instructionvalue output block that outputs instruction values for instructing theCPU 23 to instruct the operations of the camera heads 10 a and 10 b,these instruction values serving as the basis for the first and secondcontrol values. Then, the video interface block 34 of the camera controlunit 14 outputs the images received from the video interface block 24 ofthe camera adaptor box 12 to an external apparatus, not shown.

The CPU 23 of the camera adaptor box 12 receives command signals of oneline that are transmitted in a multiplexed manner from the cameracontrol unit 14 through the camera cable 15. Then, the CPU 23 outputsthe first and second control values that almost equalize the changeratio of imaging operations such as aperture and white balance of thecamera heads 10 a and 10 b to the camera heads 10 a and 10 b.

At this moment, the camera adaptor box 12 includes the following controlvalues in a received command signal and outputs this command signal tothe camera heads 10 a and 10 b. At this moment, on the basis of theinformation indicative of the imaging state at the time the camera heads10 a and 10 b execute imaging operations, the CPU 23 must set thedifferential data between the first camera and the second camerabeforehand by the first and second control values outputted to thecamera heads 10 a and 10 b. Therefore, the CPU 23 stores thedifferential data between the camera heads 10 a and 10 b and, by use ofthis differential data, functions as a correction control block foroutputting the first control value to the first camera head 10 a and thesecond control value obtained by correcting the differential data to thesecond camera head 10 b. AS a result, the camera heads 10 a and 10 b canbe handled as if these camera heads were one unit of camera by applyingthe differential data to the control command to be received from thecamera control unit 14.

With the camera adaptor box 12, a voltage control oscillator of the PLLcircuit 21 is PLL-locked on the basis of a reference signal receivedfrom the camera control unit 14. The timing generation circuit 22functions as an imaging timing adjustment block that outputs an imagingtiming signal for adjusting the imaging timings of the camera heads 10 aand 10 b to the PLL circuit 17 of the camera heads 10 a and 10 b. Thisallows the matching between the imaging timings of the camera heads 10 aand 10 b. The timing generation circuit 22 generates imaging timingsignals (T1 and T2) for use by the camera heads 10 a and 10 b,respectively. If there occurs an misalignment between the imaging timingsignals (T1 and T2) in the two cameras as a 3D image due to camera imageinversion processing for example, the imaging timing signals (T1 and T2)can be shifted together so as to correct the misalignment.

As shown in FIGS. 4A and 4B, if the mount 7 is of a rig type requiringimage inversion, it is required to match both the imaging timings of thecamera heads 10 a and 10 b and the video output timings. Therefore, thecamera adaptor box 12 has an image delay function in addition to theimage inversion function. It should be noted that, along with the imageinversion function, the image delay function may be installed on thecamera heads 10 a and 10 b or the camera adaptor box 12.

When the camera heads 10 a and 10 b receives imaging timing signals, thePLL circuit 17 executes a PLL operation on each camera head in a properphase. Hence, in the system operation, the two camera heads 10 a and 10b are simultaneously controlled, thereby allowing the camera adaptor box12 to operate as if one unit of camera.

The video interface block 24 of the camera adaptor box 12 functions as avideo output block that outputs images received from the camera heads 10a and 10 b which executed imaging operations on the basis of the firstand second control values with the imaging timings adjusted by imagingtiming signals. If the imaging device 16 is a CMOS sensor based on linescan imaging (the CCD imager is of image planar scanning), then thecamera heads 10 a and 10 b each have a function of changing the sequenceof up/down directions at the time when an image is inverted in theup/down directions. Hence, the camera adaptor box 12 can adjust theimage distortion direction caused by a rolling shutter effect.

At this moment, the video interface block 24 vertically inverts theimage received from one of the camera heads 10 a and 10 b in match withthe image received from the other camera head and outputs a resultantimage.

Next, the timing generation circuit 22 outputs an imaging timing signalto that other camera head by delaying the imaging timing by one frame.

In addition, the camera adaptor box 12 can select, as a viewfindersignal, an output from the camera head 10 a, an output from the camerahead 10 b, a mixed output from both the camera heads 10 a and 10 b, or adifferential output from the camera head 10 a to the camera head 10 band display the selected signal. Display examples of this outputtedimage will be described later (with reference to FIGS. 13A to 14C).

Further, the camera adaptor box 12 has a function of switching betweenthe main line and the return signal to output a viewfinder, signal tothe viewfinder block 13. If the viewfinder block 13 is compatible with3D image display, the viewfinder block 13 can receive a 3D viewfindersignal from the video interface block 24 to display a 3D image. In thiscase, the video interface block 24 can add characters (or characterinformation) and markers, for example, that are displayed on theviewfinder block 13 to the viewfinder signal so as to display thesecharacters and markers in a 3D manner. For this purpose, the cameraadaptor box 12 can set characters and markers at any distances byputting these characters and markers into the consideration of 3Dperspective effect.

It should be noted that, for an exemplary application, the differentialdata for camera control may not be stored in the camera adaptor box 12.For example, the differential data may be stored in the camera head 10 aor the camera head 10 b to manipulate, inside the camera head 10 a orthe camera head 10 b, the control data (or commands) supplied from thecamera control unit 14. Control items include most of the camera controlitems, such as iris, white balance, pedestal, gamma, filter, flair,black gamma, knee, and saturation.

Referring to FIG. 6, there is shown an exemplary internal configurationof the camera adaptor box 12.

The camera adaptor box 12 has a reception block 27 for receiving commandsignals entered over the camera cable 5 and a transmission block 28 fortransmitting video signals received from the camera heads 10 a and 10 bto the camera control unit 14.

Further, the camera adaptor box 12 has a timing generation circuit 22for generating imaging timing signals (T1 and T2) for simultaneouslycontrolling the camera heads 10 a and 10 b by a PLL operation of the PLLcircuit 21. In addition, the camera adaptor box 12 has genlock circuits29 a and 29 b for transmitting imaging timing signals (T1 and T2) to thecamera heads 10 a and 10 b with predetermined timings, therebygenlocking the camera heads 10 a and 10 b.

In addition, the camera adaptor box 12 has a video interface block 24for receiving video signals (C1 and C2) from the camera heads 10 a and10 b and transmitting a viewfinder signal to the viewfinder block 13 andtransmitting the video signals (C1 and C2) to a video interface block 26in the next stage.

The video interface block 24 outputs, to the viewfinder block, any oneof an image outputted from the camera head 10 a, an image outputted fromthe camera head 10 b, a mixed image outputted from the camera heads 10 aand 10 b, a differential image obtained by subtracting the imageoutputted from the camera head 10 b from the image outputted from thecamera head 10 a, divided images obtained by dividing the imagesoutputted from the camera heads 10 a and 10 b at the center of screen,the divided images being simultaneously displayed, and a 3D image.

Further, the camera adaptor box 12 has the video interface block 26 fortransmitting a reference signal received by the reception block 27 tothe PLL circuit 21, transmitting a return signal to the video interfaceblock 24, and transmitting and receiving command signals with the CPU23. The video interface block 26 also has a function of transmittingvideo signals (C1 and C2) received from the video interface block 24 toa transmission block 28.

Referring to FIG. 7, there is shown an exemplary internal configurationof the video interface block 24.

The video interface block 24 has FIFO memories 31 a and 31 b for storingvideo signals entered from the camera heads 10 a and 10 b, respectively,in a first-in first-out basis, memories 33 a and 33 b for temporarilystoring video signals read from the FIFO memories 31 a and 31 b, andfilter blocks 32 a and 32 b for appropriately accessing the memories 33a and 33 b to horizontally and vertically filter the video signals. Thevideo interface block 24 also has the video interface block 34 foroutputting the video signals (C1 and C2) received from the filter blocks32 a and 32 b to the video interface block 26. The video interface block34 also has a function as a selector for selecting one of the videosignals (C1 and C2) to be outputted to the video interface block 26.

In addition, the video interface block 34 has a viewfinder signalprocessor 35 for generating viewfinder signals outputted to theviewfinder block 13 by the video signals received from the filter blocks32 a and 32 b. The viewfinder signals are outputted to the viewfinderblock 13. The viewfinder block 13 displays various viewfinder imagesaccordingly.

The video interface block 24 has a FIFO memory 36 for storing a returnsignal received from the video interface block 26, on a first-infirst-out basis. The return signal read from the FIFO memory 36 istransmitted to the video interface block 34 for use in a predeterminedprocessing operation.

Referring to FIG. 8, there is shown an exemplary internal configurationof the CPU 19 a of the camera head 10 a, the CPU 10 b of the camera head10 b, and the CPU 23 of the camera adaptor box 12.

The CPU 23 of the camera adaptor box 12 has camera adaptor data 41 forcontrolling operations of the camera adaptor box 12, a correctionprocessing block 43 for executing correction by predetermined correctionfunctions, and correction data 42 that is entered in the correctionprocessing block 43. The camera adaptor data 41 and the correction data42 are stored in a memory, not shown.

The CPUs 19 a and 19 b of the camera heads 10 a and 10 b have camera,data 45 a and 45 b for providing data unique to the camera heads 10 aand 10 b on the basis of the control signals received from the CPU 23,and trim data 46 a and 46 b for correcting the individual differences ofthe camera heads 10 a and 10 b, respectively. In addition, the CPUs 19 aand 19 b has adding blocks 47 a and 47 b for adding the trim data 46 aand 46 b to each control signal and a DSP (Digital Signal Processor) 48a and DSP 48 b for controlling operations of the components of thecamera heads 10 a and 10 b on the basis of control signals received fromthe adding block 47 a and 47 b.

The following describes each of the above-mentioned components.

First, the control panel 11 outputs a control signal to the cameraadaptor box 12, thereby outputting a predetermined control command.Next, the CPU 23 stores the command received from the control panel 11into camera adaptor data 41 and controls the camera head 10 a asinstructed by the stored command. It should be noted here that theoperations of the camera heads 10 a and 10 b in mechanism or softwaremay not actually match each other even if the imaging conditions of thecamera heads 10 a and 10 b are equal between the camera heads 10 a and10 b. A mismatch between the operations of the camera heads 10 a and 10b is referred to a “difference.” The camera adaptor box 12 eliminatesthis difference to prevent the images taken by the camera heads 10 a and10 b from being shifted.

The camera adaptor box 12 has correction data 42 for correcting thedifference between the camera heads 10 a and 10 b. On the basis of theoperation of the camera head 10 a, the difference to the operation ofthe camera head 10 b relative to the operation of the camera head 10 ais corrected by the correction processing block 43. Consequently, thecamera adaptor box 12 corrects the command from the control panel 11 bya given function, thereby controlling the camera head 10 b. For example,the correction processing block 43 can correct the irises of the cameraheads 10 a and 10 b by use of a correction function to be describedlater.

Hence, the control signal for operating the camera head 10 a isoutputted to the camera head 10 a without being corrected by the cameraadaptor box 12. The CPU 19 a in the camera head 10 a corrects thecommand issued from, the control panel 11 by given camera data 45 a andtrim data 46 a to the control signal and then outputs a command to theDSP 48 a. Consequently, the DSP 48 a controls the operation of thecamera head 10 a.

On the other hand, the control signal corrected by the correctionprocessing block 43 is outputted to the camera head 10 b. The CPU 19 bin the camera head 10 b gives camera data and adjustment data to thecontrol signal to correct the command issued from the control panel 11and outputs the corrected command to the DSP 48 b. Consequently, the DSP48 b controls the operation of the camera head 10 b.

The camera heads 10 a and 10 b installed on the mount 7 are arranged sothat the lens optical axes cross each other at right angles as shown inFIGS. 4A and 4B and the camera head 10 a outputs a video signal withup/down and left/right directions aligned relative to a subject.However, the camera head 10 b is arranged with the imaging direction inwhich imaging is done by the camera head 10 b inverted. Therefore, theimages outputted by the camera heads 10 a and 10 b are inverted in thevertical image.

Therefore, if the vertical direction is inverted, the video interfaceblock 24 in the camera adaptor box 12 delays the output of the videosignal received from the camera head 10 a by a time equivalent to onefield and outputs the delayed signal. On the other hand, because theline scan of the video signal received from the camera head 10 b isopposite in direction with the line scan of the video signal receivedfrom the camera head 10 a, the video interface block 24 makes adjustmentso that one field of the video signal is stored and outputted bysubstantially the similar line scan to the video signal received fromthe camera head 10 a. This processing allows the camera adaptor box 12to provide synchronization between the frames of the video signalsreceived from the camera heads 10 a and 10 b and output the synchronizedvideo signals to the camera control unit 14.

Referring to FIGS. 9A and 9B, there are shown examples in which matchesare made between the imaging timings and video output timings of thecamera heads 10 a and 10 b by changing scan directions if the cameraheads 10 a and 10 b are of sequential scan type as CMOS sensors.

It is assumed that FIG. 9A shows an image being taken by the camera head10 a, then FIG. 9B shows an image being taken by the camera head 10 b.At this moment, the vertical scan sequence of the camera head 10 b maybe inverted to make the imaging time of the image match that of thecamera head 10 a and also match the video output timing (the camera head10 b has a function of setting scan directions as desired).

FIGS. 10 through 12 show examples of correction functions that are usedby the correction processing block 43 to correct the iris of the camerahead 10 b.

Referring to FIG. 10, there is shown an example of iris adjustmentvalues to be given to the camera heads 10 a and 10 b and actual irisapertures.

First, an iris control signal is transmitted from the control panel 11to the camera adaptor box 12 via the camera control unit 14. This iriscontrol signal is used for an iris adjustment value for adjusting theirises of the camera heads 10 a and 10 b.

It is desired here that the iris adjustment value indicated by thecamera control unit 14 and the iris aperture value at the time theirises of the camera heads 10 a and 10 b are actually driven changeideally along a line 50. However, the figure is indicative that the irisaperture of the camera head 10 a changes along a correction function 51and the iris aperture of the camera head 10 b changes .along a line 52.Hence, there possibly occurs a difference between the iris apertures ofthe camera heads 10 a and 10 b relative to the iris adjustment value,thereby resulting in differences in luminance and so on of the takenimage. Therefore, by use of a correction curve shown in FIG. 11, the CPU23 converts the iris adjustment value transmitted to the camera head 10b into the control value of the iris adjustment value transmitted to thecamera head 10 a.

Referring to FIG. 11, there is shown an example of iris adjustmentvalues to be given to the camera heads 10 a and 10 b.

As described above, although the same iris adjustment value is used onthe camera heads 10 a and 10 b, the camera heads 10 a and 10 b usedifferent iris apertures. Hence, with reference to the camera head 10 a,the degree of change for the camera head 10 b is defined by a curvecorrection function. The values of the correction function changes fromtime to time depending on the correction data 42. As shown in thefigure, the change in the iris adjustment value to be given to thecamera head 10 b can be made go along a correction function 51indicative of the change in the iris adjustment value to be given to thecamera head 10 a, thereby operating the camera heads 10 a and 10 b witha same iris aperture.

Referring to FIG. 12, there is shown an example of iris adjustmentvalues to be given to the camera heads 10 a and 10 b.

The correction function 51 shown in FIG. 12 is generally the same as thecorrection function 51 shown in FIG. 11 except for plots 53 a through 55a specified on the correction function 51 shown in FIG. 10 that are forapproximating the correction 51 with a dotted line. The correctionvalues of the iris adjustment values of the camera heads 10 a and 10 bare measured in advance, and then the correction function isapproximated by the dotted line on the basis of the measured correctionvalues. At this moment, plots 53 b through 55 b in the iris adjustmentvalue to be given to the camera head 10 b are corrected in match withthe plots 53 a through 55 a, respectively.

FIGS. 13A to 14C show examples of images that are displayed on theviewfinder block 13.

The camera adaptor box 12 can select, as a viewfinder signal, an outputimage of the camera head 10 a, an output image of the camera head 10 b,a mixed output image of the camera heads 10 a and 10 b, and adifferential image between the output images of the camera heads 10 aand 10 b and display the selected image on the viewfinder block 13.

Then, the engineer can operate a menu interface displayed on theviewfinder block 13, a rotary switch attached to the camera adaptor box12, or allocate push switches or sequentially operate the push switches,thereby selecting images to be displayed on the viewfinder block 13. Theengineer can also switch an image to be displayed on the viewfinderblock 13 to a return signal in response to a request for receiving fromthe camera control unit 14 or the like, thereby outputting the returnsignal. In addition, if the viewfinder block 13 is compatible with 3Dimage display, the engineer can display images for two channelsoutputted from the left and right channels and add a selection menu forthis purpose.

FIG. 13A shows an example of an image of the right channel that isoutputted from the camera head 10 a.

FIG. 13B shows an example of an image of the left channel that isoutputted from the camera head 10 b.

Because the camera heads 10 a and 10 b are arranged on the mount 7 inmatch with the parallax of user, a horizontal shift is observed betweenthe images of the right channel and the left channel.

FIG. 13C shows an example of a mixed image obtained by mixing the imagesoutputted from the camera heads 10 a and 10 b.

A mixed image is obtained by adding a luminance signal and a chrominancesignal (Lch_Y, Lch_CB, Lch_CR) of the camera head 10 b (the leftchannel) to a luminance signal and a chrominance signal (Lch_Y, Rch_CB,Rch_CR) of the camera head 10 a (the right channel). This mixed signalis colored.

FIG. 14A shows an example of a differential image. A differential imageis a gray image obtained by subtracting a video signal outputted fromthe camera head 10 a from a video signal outputted from the camera head10 a. FIG. 14A shows a differential image obtained by taking a videochart. At this moment, the video interface block 24 displays thedifferential image on the viewfinder block 13 on the basis of adifference between the luminance signal or chrominance signal of animage taken by the camera head 10 a and the luminance signal orchrominance signal taken by the camera head 10 b.

The differential image is obtained by subtracting the luminance signal(Rch_Video) of the camera head 10 a (the right channel) from theluminance signal (Lch_Video) of the camera head 10 b (the left channel).It is also practicable to subtract the luminance signal of the camerahead 10 b (the left channel) from the luminance signal of the camerahead 10 a (the right channel). Then, an obtained differential value isdivided by 2 or another proper number and a result of the division isadded with a video level (50_Video_Level) of a proper value as anoffset.

The above-mentioned explanation can be expressed as follows:

(Lch_Video−Rch_Video)/2+50_Video_Level

As a result, a differential image with attention put only on luminancecan be displayed on the viewfinder block 13.

Likewise, it is practicable to create differential data on the basis ofchrominance data. At this time, a difference is obtained by subtractinga chrominance signal (Rch_CB, Rch_CR) of the camera head 10 a (the rightchannel) from a chrominance signal (Lch_CB, Lch_CR) of the camera head10 b (the left channel).

(Lch_CB−Rch_CB)/2 or (Lch_CR−Rch_CB)/2

It should be noted, however, that, because point 0 is the intermediatepoint, an offset value need not be added in this case. For highlighteddisplay, color intensification may be made by the multiplication by aproper value without the division by 2.

Thus, a monochrome mode in which only luminance is displayed as adifferential image and a color mode in which chrominance data is addedcan be displayed on the viewfinder block 13.

If the zoom and direction of the camera heads 10 a and 10 b arecorrectly arranged, there occurs no shift in video, so that a resultantdifferential image is in an ideal state in which no outline isdisplayed. However, if there is a difference between the arrangements ofthe camera heads 10 a and 10 b, there occurs a shift between the twoimages, resulting in the enhanced outline of the subject as shown on theleft side in FIG. 14A. This provides information that is effective incorrectly setting the zoom and direction of the camera heads 10 a and 10b set on the mount 7.

FIG. 14B shows an example of an anaglyph image.

In related art, an anaglyph image is used to provide a 3D image. Forexample, through a red cellophane film for the left eye and a bluecellophane film for the right eye, the user can get a 3D image effect.

FIG. 14C shows an example of divided image obtained by dividing images.

In this example, the right half of an image outputted from the camerahead 10 a and the left half of an image outputted from the camera head10 b are connected with each other at the centers thereof, the resultantimage being displayed. This allows the engineer to understanddistortions and the like of the installation positions of the cameraheads 10 a and 10 b, making it easy to align the distortions in thehorizontal direction. It should be noted that, although not shown, theupper half of an image outputted from the camera head 10 a and the lowerhalf of an image outputted from the camera head 10 b may be connectedwith each other at the center thereof. In this case, it becomes easy toalign the distortion in the vertical direction of the camera heads 10 aand 10 b.

According to the above-described camera adaptor box 12 practiced as oneembodiment of the invention, a differential value of an operation of thecamera head 10 b relative to the camera head 10 a is obtained withreference to an operation of the camera head 10 a. Then, the operationof the camera head 10 b is controlled on the basis of the differentialvalue. Consequently, in outputting, from the control panel 11, a controlsignal for the camera adaptor box 12 to control operations of the cameraheads 10 a and 10 b, the engineer can control the two units of thecamera heads 10 a and 10 b as if the camera heads 10 a and 10 b were oneunit of camera head. In addition, because the camera heads connected tothe camera adaptor box 12 look like one unit from the camera controlunit 14 constituting the camera systems 2 and 3, the configuration ofthe camera systems 2 and 3 will not be complicated. Further, the cameraheads 10 a and 10 b output the homogeneous images with the differencesthereof removed, so that effects can be obtained that an output suitablefor a 3D image in which two images are combined for display is obtained.

In order to operate a system of two or more (3D) cameras (in thisexample, the camera heads 10 a and 10 b) or largely extend the distancebetween the camera, the control panel, and the device that receivesvideo signals, a system configuration having a camera control unit (CCU)can be provided. Consequently, the volume of wiring to the camera side(the camera heads 10 a and 10 b and the camera adaptor box 12) can bereduced to realize the flexible operation of the linked imaging with twoor more cameras such as live system cameras. This novel configurationenables 3D cameras to realize a system camera configurationsubstantially similar to that based on related-art 2D imaging.

Besides, the engineer can simultaneously control the camera heads 10 aand 10 b while correcting the difference between the camera heads 10 aand 10 b by use of a correction function and so on. This facilitates thecooperative linkage between the camera heads 10 a and 10 b. Thus,handling the two units of the camera heads 10 a and 10 b used in the 3Dcamera systems 1 through 3 facilitates the camera operation (livecoverage, relay, and so on) in 3D camera systems.

The timing generation circuit 22 of the camera adaptor box 12 canprovide a match between the imaging timings in accordance with theoutput timing of an image in which a difference has occurred to adjustthe imaging timings of the camera heads 10 a and 10 b, therebysimultaneously taking a subject. In addition, the video interface block24 executes processing such as inverting an image outputted from thecamera head 10 b in match with the imaging timing outputted by thetiming generation circuit 22, thereby matching the outputting timing ofthe image outputted from the camera adaptor box 12. Therefore, inmatching the images outputted from the camera heads 10 a and 10 b as a3D image, the images having no feeling of unnaturalness can beoutputted.

Further, by use of the images outputted from the camera heads 10 a and10 b, not only the image for each channel, but also a mixed image, adifferential image, a anaglyph image, and a divided image can beoutputted to the viewfinder block 13 and a display device, not shown.Therefore, effects can be obtained that the adjustment of the irises andsetting positions of the camera heads 10 a and 10 b are facilitated.

2. Variations

It should be noted that, in the above-described embodiment, irisadjustment values are set for the correction made by use of correctionfunctions, the correction may also be made for zoom setting values andso on by use of correction functions. The values to be correction arenot limited to iris and zoom values.

In the above-described embodiment, an example has been described inwhich the camera heads 10 a and 10 b have no viewfinder block; however,it is also practicable that the two units of cameras each have aviewfinder block.

The above-mentioned sequence of processing operations may be executed bysoftware as well as hardware. When the above-mentioned sequence ofprocessing operations is executed by software, the operations can beexecuted by a computer in which the programs constituting the softwareare installed in dedicated hardware equipment or a computer in which theprograms for executing various functions are installed. For example, theprograms constituting the desired software may be installed into ageneral-purpose personal computer or the like for the execution ofvarious functions.

Further, a recording media storing the program codes of software forrealizing the functions of the above-mentioned embodiments may besupplied to the system or apparatuses concerned. It is also practicableto realize the above-mentioned functions by making the computers (or thecontrollers such as CPUs) of the system or apparatuses read programcodes from the recording media for execution.

The above-mentioned recording media for storing program codes include aflexible disk, a hard disk, an optical disk, a magneto-optical disk, aCD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, or a ROM,for example.

Executing program codes read by the computer realizes the functions ofthe above-mentioned embodiments. In addition, on the basis of theinstructions given by these program codes, the operating system (OS) andso on running on the computer execute part or all of the actualprocessing. The above-mentioned functions of the above-mentionedembodiments are also realized by this execution processing.

While preferred embodiments of the present invention have been describedusing specific terms, such description is for illustrative purpose only,and it is to be understood that changes and variations may be madewithout departing from the spirit or scope of the following claims.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2009-292608 filedin the Japan Patent Office on Dec. 24, 2009, the entire content of whichis hereby incorporated by reference.

1-7. (canceled)
 8. A video camera system comprising: a first imagesensor configured to output a first image: a second image sensorconfigured to output a second image: a memory configured to storecorrection data for correcting a difference between an imaging state ofthe first image sensor and an imaging state of the second image sensor;and circuitry configured to simultaneously control the first imagesensor and the second image sensor, determine a first control value anda second control value based on the correction data for the differencebetween the imaging state of the first image sensor and the imagingstate of the second image sensor, output the first control value to thefirst image sensor, output the second control value to the second imagesensor, control imaging timings of the first image sensor and the secondsensor, output the first image and the second image to a display to bedisplayed as a three-dimensional video on the display, and wherein thefirst control value is difference from the second control value.